PROBLEM TO BE SOLVED: To provide a construction machine capable of preventing a person other than an operator from operating the same even when the engine is in operation.SOLUTION: A hydraulic shovel comprises: a wireless authentication device 52 which performs wireless authentication between the same and a portable key 51; and a vehicle body controller 48 which starts an engine on the basis of the authentication by the wireless authentication device 52 and operation of a start-up switch 12. The wireless authentication device 52 transmits a request signal to an area where authentication is available and performs the authentication when receiving an ID code for the authentication sent back from the portable key 51 in response to the request signal. The vehicle body controller 48 prohibits drive of a hydraulic actuator while the portable key 51 is outside the area where the authentication is available even when a lock lever is switched to an unlock position.SELECTED DRAWING: Figure 5
